This summer England and Wales experienced the driest July since records began almost two centuries ago. As a nation, we have spent the past few months improvising. From taping tin foil and cardboard over windows to sleeping on kitchen floors and in gardens, close to nine million people took drastic action of some kind to get through this summer. None of this is a solution, it is what people resort to when the buildings around them cannot do the job.

The instinct now will be to bolt cooling onto homes that were never designed to shed heat. Derek Horrocks, owner and chair at Sustainable Building Services (UK) Ltd and chairperson of the National Home Decarbonisation Group (NHDG), explains why this is not just a weather story but a housing story, and it needs to be treated as such.

The market has already moved

Rightmove recently reported that buyer searches for homes with air conditioning rose by 104% between May and July this year, compared with the same period last year. This is becoming more of a priority to homebuyers, as almost nine in ten also said that a home’s ability to stay cool matters when choosing their next move. Agents are therefore likely fielding questions about everything from ventilation and glazing to natural shade and orientation, because buyers want to know what a property will actually feel like to live in across the seasons. That is a considerable shift from asking what a home has to asking how it performs.

This is not just reserved for people who are currently house hunting too. Ipsos polling conducted at the start of August found that 74% of British adults are concerned about climate change, up from 69% who recall feeling that way before the summer. However, most strikingly, 87% of respondents think that it is likely Britain will see similar severe heatwaves in future summers – interpreting that people believe this is the new normal. But it is worth asking whether the buildings we are investing in over the next decade will have reached the same conclusion.

For anyone who owns housing stock, that reframes the conversation entirely. Thermal comfort has stopped being a comfort question and become an asset value question instead, homes that cannot hold a stable temperature will be worth less, cost more to run and become harder to let.

But the market only helps people who can move

A buyer who cares about glazing and orientation can act on it, whereas a tenant cannot. This is where it stops being about property listings and starts being about who is protected. Citizens Advice found that 51% of renters feel like they lack the basic control needed to stop their homes from overheating, against 40% of homeowners. Some of this is based on design, but some of it is simply locked windows and a thermostat no one is allowed to touch. Its research into heat networks found that around 38,000 households cannot turn their heating off even during the summer, meaning that hot pipework is often driving indoor temperatures up while the resident has no means of intervening.

Additional analysis by the National Housing Federation and the Chartered Institute of Housing found that 1.59 million children are in homes that get uncomfortably hot, of whom around 70,000 are under the age of one.

The government’s Warm Homes Plan makes this point bluntly. It identifies that urban high-density flats and terraced houses in those denser areas are the stock most vulnerable to overheating, and it also notes a correlation between the people most vulnerable to heat stress and those most likely to be living in exactly those property types in the first place.

The law is about to formalise it

From 30 November, and subject to parliamentary approval, phase two of Awaab’s Law brings excess heat into scope alongside excess cold, fire and electrical hazards. Where a hazard presents a significant risk of harm, investigation and repair timescales apply. Where a home cannot be made safe within those timescales, the landlord must arrange suitable alternative accommodation instead.

One thing that needs considering though, and landlords should not underestimate, is how different heat is from damp. Damp leaves longstanding issues such as black mould, which can be a lengthy and expensive process to get rid of, whereas excessive heat typically leaves nothing behind. It is completely seasonal and subjective, it also varies by floor and property positioning, with the severity of it also depends heavily on who is living there. A temperature that is uncomfortable for one resident is dangerous for a person with a respiratory condition or a newborn, and the guidance is explicit that these reports cannot be written off as a lifestyle issue.

The practical consequence is that you cannot wait for the complaints to arrive in June and then triage them. By the time the reports do come in, the clock is already ticking, and the evidence is becoming quickly outdated as extreme weather begins. Understanding which parts of your stock overheat, and which residents are exposed to it, is work that must happen before the weather does it for you.

The wrong answer and the right one

It is reasonable to think that the quickest response to this is to install cooling measures, but it is also the most expensive one. Typically, this lands the cost on the resident rather than the landlord. Citizens Advice documented a housing association tenant who went £40 into electricity debt in a single month running a portable unit, and who was more worried about the bills from the permanent units her landlord had promised than she was relieved by them. Bolting active cooling onto a poorly performing building layers a running cost problem on top of an efficiency problem and adds demand to an electricity network we are already asking to absorb the transition away from gas.

The evidence for the alternative option is in the Warm Homes Plan itself. A case study referenced within the document describes how a monitored flat in Camden, single aspect with no cross ventilation, reached 47.5 degrees in the bedroom when it was 28 degrees outside. External shading combined with night-time ventilation removed the overheating risk entirely and brought indoor temperatures down by 11 to 18 degrees. Internal blinds on their own achieved nine to 13 degrees, roughly three quarters of the benefit of external.

However, this is not an argument against cooling technology, for example, air-to-air heat pumps now attract a £2,500 grant under the Boiler Upgrade Scheme (BUS), and they heat as well as cool, making them a sensible part of the answer. But it is imperative to get the sequencing right, getting the fabric and shading right first and any active cooling you then install works harder for less money.

What landlords should be doing now

From 2027/28 the Warm Homes Social Housing Fund and the Warm Homes Local Grant are set to merge into a single scheme with a deliberate shift towards area-based delivery. Retrofit fundamentally works best street by street rather than property by property, because the archetypes repeat and the cost per home falls through economies of scale.

What has to change is the assessment underneath it, as for years a whole-house survey has meant a winter survey, looking at heat loss and little else. The same visit needs to establish how a home behaves in August as well as February, because the measures that fix one can make the other worse if nobody has monitored properly.

This is a problem that isn’t going away either, as the Met Office has warned that the El Niño developing in the Pacific is likely the strongest in living memory, with 2027 very likely to be the warmest year on record globally. For the UK, the nearer-term signal is a wetter, stormier autumn and winter. A record dry summer followed by a saturated one, in the same homes, with the same fabric problem behind both.

For most landlords setting stock investment plans for the next five years, it is worth remembering that the survey you commission this year determines what you can do with that money. So, make sure to ask for the summer picture alongside the winter one, and you will only need to invest once.